Injection Molding Success Story
Better Release for Low-Draft,
High-Precision Details
Harvey Bruce, of Thermotech, located in Hopkins, MN, had a tough release problem with one of his critical thermoplastic molds. He turned to Phygen for help with this problem, and came away with three problems solved. His experience shows that FortiPhy™ coatings by Phygen is the right solution for increasing corrosion resistance of plastic molds, while also improving wear resistance and release characteristics.
 Thermotech regularly solves thermoplastic molding challenges that others will not tackle. They understand the extremes of thermoplastic molding, from automotive and aircraft parts produced on a 550-ton machine, to micromolded 0.001 gram parts with tolerances as low as ±1-micron. Regardless of the application, Thermotech demands the best-performing molds and tooling possible.
According to Bruce, Thermotech needed to improve the release properties of several molds used to form precise cylindrical bobbins for electronic solenoids. These particular parts contain a tiny wire-retaining slot with extremely tight tolerances (±.001-inch). Low draft in the wire slot was causing “pulling” problems and slowing production. Bruce explains, “With a whole department dedicated to producing these parts, release problems had the potential to really hurt our production.”
Bruce tried several commercial coatings, from spray-on release agents to commercial “diamond-like” coatings, with little success. According to Bruce, “The spray-on release agent required a recoat every 8,000 shots, and the commercial coatings peeled, chipped, and wore off. I really needed something better, and more durable.”
He contacted Dave Bell of Phygen for a solution. Phygen applied a custom-tuned layer of FortiPhy coating to the working surface of the mold. After setting up and making a few production runs, Bruce saw the results he had hoped for. The release problem was solved, and the tight ±.001-inch tolerance was preserved.
In addition to solving his release problem, Bruce discovered that FortiPhy provided two additional benefits. Mold wear properties were improved, and the mold vents no longer were being eaten away by corrosive gas burn. In one conventionally coated mold, abrasion and gas burn had caused gas vents and details to wear after only 2,600 shots. The gas vents were destroyed after 8,000 shots (in just eight hours). After coating with FortiPhy, the same mold showed no corrosion after more than 50,000 shots.
The key to FortiPhy's exceptional toughness, low coefficient of friction, and corrosion resistance is its uniform, nanocrystalline structure. Phygen’s patented plasma acceleration process improves upon traditional PVD methods to produce the most uniform coating deposition layer possible, with exceptionally high adhesion. Having solved the uniformity problems inherent in the PVD processes of the past, Phygen can apply thinner coatings that outperform thicker, less-uniform coatings. In addition, Phygen's coatings are applied at much lower temperatures. Low-temperature processing and thinner coatings help to keep critical tool dimensions within tolerance, without the costly rework of other processes.
Thermotech was an early tester of FortiPhy coatings. Now, they are sold on them. According to Bruce, applications of FortiPhy were successful in increasing mold life in all test cases. They plan to use FortiPhy coatings on future molds, wherever there is a need to extend tool life.
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